


Sharp

by Interverse



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell (Undertale), Alternate Universe - Underswap (Undertale), Cock Piercing, Don't Try This At Home, Genital Piercing, I'm Talking like They Do the Piercing and Then Fuck Right After, M/M, Oral Sex, Piercings, Plot What Plot/Porn Without Plot, Vaginal Sex, bottom red
Language: English
Status: Completed
Published: 2019-07-14
Updated: 2019-07-14
Packaged: 2020-06-27 15:41:55
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,993
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19793935
Author URL: https://archiveofourown.org/users/Interverse/pseuds/Interverse
Summary: Piercings and ectoflesh have a strange relationship, and Red is curious to see how far he can take things. Blue is a lot more willing than he originally anticipated.





	Sharp

**Author's Note:**

> Reuploaded from my Cherryberry oneshot book.

Kisses were often viewed as foreplay or prerequisites to the main event if they were carried out with passion, but Blue disagreed. He wanted to drink his lover in, taste him and feel him and guarantee that the monster he loved knew it. With his enthusiasm, though, it was no question that he’d eventually go overboard and do a bit of damage. Such as now, in their room, where Blue had been making it his apparent mission to take the other’s breath away. But when Red make a gruff, muffled noise of surprise into his mouth, Blue pulled back, concerned he had hurt his partner. Confusion was another thing that plagued him at first, but when he realized what had happened, he brought his hand up to his mouth and opened it. Two pieces of metal fell out, both of them small golden spheres with a post attached to one of them. He looked back up at Red, concern glittering in his eyelights. “Red? I’m sorry, are you okay?”

His alternate made a face, then stuck his tongue out. Blue examined the little indent and barely visible hole in the magic flesh where the metal had previously been embedded, to find the magic was undamaged. “Uh, yeah.”

Piercings are a bit hard to achieve when most of the soft parts you have are only there temporarily, so the only thing a skeleton could pierce was their tongue. Blue had always been fascinated by Red’s; it created some interesting and certainly not negative sensations when they kissed or when his counterpart put his mouth… elsewhere, not to mention that it looked pretty cool as well.

With a breath, Blue handed the piercing back over to the other monster, presumably to be put back in so they could continue, but Red only looked down at it, cocking his head. When he looked up, his eyelights were twinkling with mischief. “Hey sweetheart, I've got an idea.”

Blue eyed him curiously. “Mind telling me?”

“What if we put this somewhere else?”

“Um, where?” Again, that was pretty much impossible for them and-

“My dick.”

Blue spluttered. “W-What?”

Red chuckled. “I mean, why not? It would fall out once I de-manifested, sure, but eh, it could be fun, right?”

Blue was having a very hard time understanding how pushing a sharp piece of metal through your genitals would be fun. “So… you only want to try… because you think it would be fun..?” He let out a breath. “Okay, fine, sure. I’m assuming you wanted me to help you?”

Red nodded. “Uh, yeah. You’d have a better view, heh.” His cheeks dusted over with his magic, and he smiled sheepishly.

Blue shook his head, but allowed himself a small smile. “Alright. But we need to disinfect the piercing first.”

Red sighed, and handed it over. Blue had always found it to be unnecessarily sharp. Here in his universe, the piercing would have been blunt and he'd need a needle, but apparently the Fell universes deemed that a waste of time. Upon returning with the sanitized pieces of metal, Blue hopped back up onto their bed and faced his lover. “Okay, so, step one, manifest.”

Red nodded, trying to fight his blush and concentrate at the same time before he pulled the waistband of his shorts down to free the magic he had forced into his pants. Forming your magic at will was quite a bit different than doing it subconsciously out of arousal - or more uncommonly, with the need to urinate after consuming human drinks. In Red’s current case, the magic was a lot more malleable, though it still looked relatively the same as it did when aroused.

Blue reached out and gripped the head of Red’s magic with a few of his fingers to hold it in place, then positioned his other hand, the piercing held in it. He shot Red a hesitant look. “You’re sure about this?”

Red nodded, shifting a bit. “Yep, I am fully prepared to have my dick sliced and diced. Hit me up.”

Blue rolled his eyes with a small smile that melted away into a grimace when he pressed the sharp tip of the metal post up to Red’s magic. He waited for another nod of approval, which he received, then gritted his teeth and pressed the metal into the ectoflesh before him. The Fell skeleton hissed, body tensing, and Blue winced at the knowledge of Red’s pain, but kept applying pressure to the piece of metal until the post poked out of his magic in a different location. Blue moved his hand down on Red’s cock, taking a second to examine what he had done. The metal went in through his urethra, then resurfaced on the underside of the magic, just before the first of the ridges that also resided there.

He glanced up at his partner, eyelights gleaming with concern. “Are you okay? Should I take it out?”

“Nah,” Red huffed, his cheeks flushed as he gripped their blankets for support. “It obviously hurts like a motherfucker, but screw it on, love, will ya?”

Blue hesitantly nodded, then glanced back down at Red’s magic, and thought that it looked a bit different for a moment, but the notion was quickly pushed from his mind when a drop of translucent, magical blood seeped from the wound and began to slide down the underside of the skeleton’s length. Finding himself without any other options, Blue clumsily undid his bandana with one hand and then brought the soft fabric down to the bit of liquid in order to sop it up, then held it against the area that had leaked the blood.

“It’s fine,” Red huffed. “M’not gonna die of magic loss or anything.”

“Okay,” Blue sighed, setting his bandana down and eyeing Red’s magic for a few more moments to be sure no more blood was going to find its way out of the wound. None did, so Blue grabbed the other end of the barbell and slowly screwed it onto the exposed area of the post. He removed his hand with a huff, and the magic he had been holding bobbed in the air more than it should have once it was released. That, along with a particularly labored breath from Red, prompted another careful look at the Fell monster’s magic.

Blue slowly extended his hand again and wrapped it around Red’s cock before giving it a gentle squeeze. The magic didn’t sink under his fingertips, and Blue’s eyes stretched wide as he watched the tip of it glimmer with precum that hadwelled there, the drop prevented from forming properly due to the metal in the way. Cheeks warming, Blue glanced up at Red, only to find his face flushed much more severely, cheeks and nasal ridge tinted a bright crimson as the skeleton balled his hands into their blankets.

“Er… I, uh…” Red finally mumbled with a heavy breath, “Guess it was a little more fun than I was intending.”

Blue bit his tongue, then dragged his hand up along his lover’s magic and pressed his thumb to the slick patch of it before rubbing little circles into it with his thumb. Red whimpered in response, shifting his hips into a more comfortable position.

“Does this hurt?” Blue murmured, slowly sliding his hand to the base of Red’s cock and earning a heavy breath in return.

“Nah,” came the gruff, wavering reply. “The opposite, actually.”

Red’s cock throbbed in Blue’s grip, and the Swap skeleton let out a single flustered breath before leaning down and gently licking along the bottom of the other’s cockhead, feeling as the metal of the piercing pressed into his tongue. Red grunted, but Blue was able to deduct the sound was not stemmed from pain when his tongue was met with another sharp taste of cinnamon; precum. He pulled back, and rolled the head of Red’s cock around in his palm, shifting the piercing within his magic in the process.

Red exhaled heavily, shooting Blue a glance with hazy eyelights before redirecting his gaze back to his own magic. Blue thumbed the sensitive patch of magic between where the two ends of the piercing stuck out, eliciting a moan from the other that sent a shiver down his spine. He gave his companion a brisker stroke so that his fingers caught on the piercing more sharply, to which Red only made another noise, averting his eyes. Blue kept going, pumping his hand up and down the upper half his lover’s length with short, fast movements whilst reaching down with the other hand to wrap the monster’s cock in a tight grip.

Blue finally granted the other monster mercy after a particularly pathetic moan from Red and another warm dribble of precum meeting his fingertips, removing the hand he had been using to stimulate him to replace it with his mouth. He slid down the solidified crimson magic until his teeth hit the fingers of his other hand, still being used to hold Red’s cock upright. The skeleton whined and pulsed against Blue’s tongue, weakly easing himself back to be propped up by his elbows. Blue let out a shuddering breath of cold air that got him a shiver from the Fell skeleton, then rose up on his companion’s magic, flicking his tongue over the piercing and area surrounding it for a few moments before removing his other hand and sinking the rest of the way down until Red was pushing at the back of his throat.

The Fell monster coughed out a moan, giving up at that point and flopping completely down onto his back. Blue hummed around his magic, earning another whimper, then angled his head so that Red’s cockhead slipped into the sticky magic of his throat. While his alternate was able to do this and beyond with ease, he wasn’t blessed with the same apparent lack of a gag reflex, so he had to pull back after only a few seconds, but it was enough.

Blue let out a little moan of his own in contrast to Red’s sudden barrage of them, trying to push down the arousal that had snuck up on him when the first shot of his lover’s ectoplasm greeted his tongue. He pushed it to the back of his mouth, letting out a breath when the second rope of cum along with a final and defeated groan from the same monster was handed to him. Red sunk down further into the mattress with a shaky exhalation when the peak of his orgasm had faded, Blue giving his twitching magic another gentle stroke with his hand before releasing it and allowing his alternate’s cum to slide down his throat, shivering. Blue watched as the magic making up Red’s cock began to fade, and caught the piercing with his hand once it finally fell out in the last stages of the Fell monster’s de-manifestation.

Blue took a minute to regain his bearings, then looked down at his lover and placed a gentle hand atop one of his. “So… ah… was that fun enough for you?”

Red let out a single, breathy laugh, cheeks heating again. “Yeah, i-it was… thank you.” A few more minutes passed in comfortable silence as Blue absentmindedly played with the dislodged piercing in his hand, but then Red shifted. “Hey, wait.”

“Mm?”

The skeleton began to wiggle the rest of the way out of his shorts, kicking them off his ankles once he had succeeded. Blue watched as Red formed his body, then opened his legs to reveal the magic there had been turned into something else entirely. “Do it again.”

Blue shifted so he was facing him better, leaning over the other monster with his blush reigniting. “I… suppose you don’t want me to ask you if you’re sure..?”

He had managed to push his own desires down and keep from manifesting in his pants, but it wasn’t going to stay that way for long if he had to continue. “Nope,” Red said after shaking his head, then shifted his hips. “Then fuck me.”

Blue’s magic heated within his bones, and he bit his tongue, slowly separating the two pieces of the piercing again. He reached down and parted Red’s inner labia with two fingers, finding that his magic was already slick with arousal, leftover from what had happened just a few minutes prior. He pressed a finger up against Red’s entrance, then dragged the moistened phalange upwards and pressed it to his clit. Red grunted, let out a breath, and looked up at him. “Save the show for later. I think I’ll like it a lot more with a piece of metal shoved in my flesh.”

With a roll of his eyes, Blue retracted his hand. He carefully set the loose end of the golden barbell down onto their blankets, then used the newly freed hand to pinch Red’s clitoral hood between his thumb and forefinger and pulled it upwards. Red shivered, letting out a small noise. Chewing on the corner of his mouth, Blue positioned the sharp tip of metal at the magic flesh he was stretching out, slowly counted to three loud enough for Red to hear, then pushed it through. Red made another noise, and Blue honestly couldn’t tell if it was closer to a moan of pleasure or a groan of pain. He quickly nabbed the other half of the piercing before it could make its escape after that, and attached it back to the post. Blue didn’t waste a second, not waiting for any blood that might have escaped from the wound before dipping his head down between his partner’s conjured thighs and closing his mouth around his clit.

Red whined, arching his back when Blue’s tongue pressed up against the sensitive nub of magic and the metal that rested in the flesh atop it. A drop of sweat beaded on Blue’s skull, his breaths becoming more labored as his magic was growing more and more difficult to control. But, he continued, and Red was soon panting beneath him. He’d manifested in his pants at that point, so a pleading whine was all the convincing he needed. Blue sat up and freed his cock, then gripped the base and lightly pressed himself up against Red’s clit, finding that the cold, slick metal of the piercing was a strange new sensation. He had felt it on his magic before when Red pleased him with his mouth, but this was different, more ticklish and leaving him feeling incredibly desperate for more stimulation. Luckily, his companion seemed to be of the same mindset, swallowing down one of his moans and huffing defiantly. “I don’t know if you have amnesia or some shit, but if you recall, to fuck me, ya gotta shove into me first.”

Blush deepening, Blue positioned himself, and slowly sunk inside of Red’s body with a weak moan. The Fell skeleton’s magic clenched around his length, the wet warmth of Red’s ectoflesh sending little jolts down his femurs and up his spine. With a breath, Blue reached down and slipped a finger onto Red’s clit as he began to ease hips backward. Both of them panted out their own moans, one more gruff than the other. Blue pushed back inside of his partner, moving to grip one end of the barbell, and twisted the metal around in his fingers.

Red gasped, entire body giving a little jerk, and Blue would have stopped to apologize, but the moan and clench around his cock were enough to keep him at it, setting a brisk pace and finding every way he could to use the piercing to his advantage. He twisted it, moved it back and forth, pressed the metal into Red’s clit to massage it, and used it along with another of his fingers to pinch the swollen magic as well. Red squirmed, digging his claws down into their blankets as his moans got caught in his throat. Blue gave a particularly sharp thrust into his alternate with a grunt, which finally opened Red’s throat enough to let out a pathetic noise something like a gurgle and a groan.

The Swap monster furrowed his browbones, quickening his pace and abandoning the piercing in favor of stimulating his lover more accurately. “Red…” he panted, “Are y-you..?”

Red groaned from beneath him, and luckily the feeling of his walls beginning to flutter around his cock were enough to answer Blue’s question, because the monster seemed to be stripped of his ability to form coherent words.

Blue let himself go with a shudder at the reassurance, panting while his magic worked to fill the other up and stain his insides purple. Red clamped down on him with a strangled moan when the first shot of cum had entered him, the sensation drawing out the second one with ease along with a sharp gasp from Blue. When their bodies had calmed, and their breathing had slowed, Blue removed his hand from between Red’s legs and instead wriggled it under his ribcage to embrace him. The Fell monster weakly reached up and returned the hold, letting out a long, trembling breath into the crook of his neck.

After he’d managed to regain his strength, Blue gently pulled himself from Red’s arms and slowly slipped himself out of the other. He groaned, shaking his head and allowing his magic to fade before looking down at his boyfriend, love glimmering in his eyelights. “Come on, let’s get you cleaned up - and don’t dispel your magic, we should really try to disinfect it first.”

“Fine, fine,” Red sighed, shivering when Blue began to remove the piercing. “...Think you’d let me pierce you next time, sweetheart?”

Blue raised a browbone, staring down at him as slipped the metal from his magic and held the warmed pieces of material in his palm. “Not a chance.”

Red only smiled. “I never said it had to be with the actual piercing.”

“W-!?”


End file.
